She was a gorgeous blonde. He was a bumbling playboy. When they fell in love and married, his billionaire father promptly disinherited them. Undaunted, the couple settled into middle-class life, she as a homemaker and mother, he as the long-suffering employee of an irascible boss, Mr. J.C. Dithers.

The rest is comic-strip history. Ever since cartoonist Chic Young created Blondie and Dagwood Bumstead in 1930, their domestic comedy has won readers' hearts by playing on four universal themes: eating, sleeping, raising children, and earning a living. Today, 75 years later, they reign as the most famous cartoon couple in history.

On Sunday, to celebrate 75 years in the funny pages, the Bumsteads will host a gala anniversary party. When readers open to "Blondie" that day, they'll find a mythical extravaganza that includes such beloved characters as Beetle Bailey, Hagar the Horrible, Garfield, Dennis the Menace, and Dilbert. Even President and Mrs. Bush will be portrayed in the party scene.

It's being called the biggest event in comic-strip history. And no wonder. "Blondie" appears in more than 2,300 newspapers in 55 countries and is translated into 35 languages. An estimated 250 million people see it. It is consistently among the five most popular newspaper comics.

The first "Blondie" strip ran on Sept. 8, 1930. When Dagwood gave up his inheritance to marry Blondie in 1933, his choice offered a rich story line, says Kathleen Turner, professor of communications at Davidson College in North Carolina. "It meant that Chic Young could now have the penniless but infatuated young couple reassure readers that with love, humor, and perseverance, the American dream was still possible."

After Mr. Young's death in 1973, his son, Dean, took over. With artist Denis Lebrun, he produces seven strips a week from a studio in Clearwater Beach, Fla. In a telephone interview, he refers to his father as "my daddy, the genius, who created this wonderful cast of characters to work with."

Over the decades, Young has updated the Bumsteads. They now talk on cellphones. Blondie runs a catering business and owns a laptop. Dagwood uses a computer at the office. Instead of racing to catch a bus to work, he carpools. "The bus deal became old-fashioned," Young explains.

Was it hard to turn the Bumsteads into a dual-career family? "I debated a long time before I did it," Young says. "I wasn't sure what business I wanted Blondie to go into. Catering was perfect. The eating business was real close to home."

Some things haven't changed. Dagwood's unspoken motto remains: When in doubt, take a nap. "That's still his favorite sport," Young says. "He loves napping and eating. He has a black belt in buffets. And he still can't get that raise from his boss. All those things are constants."

Dagwood also still specializes in making the mile-high sandwiches that earned him a place in the dictionary. But he doesn't really cook. As for cleaning, Young says, "He's not good at it, but he will do it. Sometimes he can help clear the dishes from the table, scrape the dishes off, and get them into the dishwasher."

That kind of traditional behavior draws fans and critics.

"Those who don't like it complain of the same-old, same-old: stale conceptions of marriage set in stale story lines, in which Daisy the dog has the most interesting expressions of the entire crew," says Professor Turner, who studies images of women in comic strips.

"It surprises me that 'Blondie' has been so popular for so long," says Scott Coltrane, a sociologist at the University of California, Riverside, who grew up reading the strip. "The pejorative depiction of men as lying on the couch does not play as well with men who are trying to do more. However, it still plays well with women, because many men still do so little compared with their wives."

Still, sometimes a comic strip is just a comic strip. "Media depictions of family life cannot be taken as reflections of actual practices in American families," Professor Coltrane says. "But our preoccupation with them suggests that they carry profound public and private significance."

Family-oriented strips like "Blondie" became popular in the comic pages after World War II, says Ralph LaRossa, a sociologist at Georgia State University in Atlanta. By the 1990s, he adds, "The proportion of comics with fatherhood, motherhood, or parenthood as a theme mushroomed to nearly 25 percent."

The Bumsteads reflect a comforting timelessness. "They still look the same," says Mike Lynch, a magazine cartoonist in New York. He compares them with strips such as "Gasoline Alley" and "For Better or Worse," where characters have aged and "sag a bit." Blondie and Dagwood are frozen in their late 30s, with two young teenage children.

Will they grow older? "Not in my lifetime," Young vows.

Even with their modernized plot lines, Blondie and Dagwood still strike some readers as quaint. "My father is the only one I know who still reads 'Blondie,' " says Kelly Fitzgerald of New York.

Her father, Bill Fitzgerald of Sanford, Fla., has been reading "Blondie" for 65 years. "I don't actually know anyone that inept or who eats that much without getting fat, but I can see similarities in my life and others I have known," he says. "It makes me feel good, as they are regular people. I want to go to their party."

In an age of social upheaval, rocked by divorce and dysfunction, Blondie and Dagwood offer stability. They're still together after all these years.

"Here's a family where they actually like each other," Young says. "The husband and wife are still in love with each other. He kisses her when he leaves, and kisses her when he comes home. It's fun to look in on a family that actually is going through life in a loving, affectionate way. It's kind of a confidence builder."

Bob Madison, a pop culture historian in New York, sees other appeal. "Blondie and Dagwood share the real workaday world with us. Like all of us, they take it one day at a time, with all the little funny things that happen to us noted along the way. 'Blondie' is a slow strip. Its sweet good nature and humanist point of view are what make people return."

America's longest-running comic strips

Even at 75, Blondie's not the oldest comic strip around. The five longest-running funnies in the United States, all honored with their own postage stamps in 1995, are all on their second cartoonist, at least.

1. Katzenjammer Kids (1897-present): It retells German children's tales through twins Hans and Fritz. Created by Rudolph Dirks, it is the oldest comic strip in syndication.

2. Gasoline Alley (1918-present): Unlike the perennially young Bumsteads of "Blondie," the characters in this strip are drawn progressively older as the years go by.

3. Barney Google and Snuffy Smith (1919-present): This comic with its hillbilly characters still runs in 21 countries and in 11 languages. The strip introduced such terms as "heebie-jeebies" and "sweet mama" into the American vernacular.

4. Thimble Theater/Popeye (1919-present): The strip was centered on Olive Oyl until Popeye arrived in 1929. Popeye was the first cartoon character ever made into a public sculpture, honored for boosting Americans' consumption of spinach.